1. Field of the Invention
The present invention relates to a storage system and a method of controlling of feeding power to a storage system.
2. Description of the Related Art
A storage system comprises a storage unit, which connects a large number of hard disk drives in an array, and provides a logical storage area (logical volume) to a server or other such host computer (hereinafter “host system”). To enforce reliability and so forth, the storage system provides a host system with a redundant storage area based on RAID (Redundant Array of Independent Disks).
Now then, the data being managed by companies and so forth is increasing day by day. The more the amount of the data is increasing, the larger the number of disk drives connected within a storage system is required. Hence, the larger the number of disk drives connected within a storage system increases, the greater the amount of power a storage system consumes.
Accordingly, some methods for controlling the feeding of power to disk drives connected within a storage system have been proposed. As a first prior art, a method for planning a schedule for feeding power based on a job execution schedule in a host system (Japanese Patent Laid-open No. 9-282057) is known. As a second prior art, a method for feeding power to respective disk drives based on a utilization rate and times of powering on and off of the respective disk drives (Japanese Patent Laid-open No. 2004-252570) is known.
The above-mentioned first prior art reduces power consumption based on a job execution schedule in a host system. Consequently, in a prior art such as this, controlling the power reduction of a storage system depends on a host system, and a storage system cannot control feeding of power to a plurality of disk drives within the storage system independently.
The above-mentioned second prior art controls the feeding of power to a disk drive irrespective of the accesses from the host systems. Therefore it is difficult to reduce the access time from the host systems.